A fat, disgusting old beast, he had once been a great warrior, but in the years since he attained the rank of Jeddak, he had debased himself by indulging in every sin and vice that presented itself. By 1866, when John Carter arrived on Mars and the Tharks captured PrincessDejah Thoris of Helium, Tal Hajus' willpower was so atrophied that he was prepared to throw away the possibility of receiving an exorbitant ransom from the princess' family just for the fleeting thrill of raping her.

Unfortunately for him, he also made advances at the young Green Martian woman Sola, and that was the mistake that led to his downfall. When the JedTars Tarkas later discovered that Sola was his daughter, he demanded the right to challenge Tal Hajus' fitness as a Jeddak, arguing that the old pig's corpulence prevented him from fighting alongside his men, which was expected of all Jeddaks. Tal Hajus was forced to accept the challenge, and minutes later, he lay dead on the floor.

In the Disney film universe Tal Hajus is the result of a Warhoon and Thark pairing. He is not the Jeddak of Thark at the start of the story, but rather a high-ranking soldier (likely a Jedwar or Padwar) who challenges the authority of Tars Tarkas. At first, no other Thark will stand with him, so his challenge is not accepted. After Tars Tarkas releases John Carter, Dejah Thoris, and Sola to travel down the Iss, Tal Hajus finds support among the Tharks and challenges Tars Tarkas once more, wresting the title of Jeddak from him. In the few days/weeks before John Carter and Sola return to Thark, Tal Hajus has already become a lackadaisical and slovenly ruler of the Tharks. He sentences Carter and Tars Tarkas to fight in the arena against a pair of White Apes, but Carter dispatches them. The human then challenges Tal Hajus. The angered Thark jumps into the arena, blade at the ready, but Carter cuts his head from his body before the green man even touches the ground. Now having taken the title of Jeddak from Tal Hajus, Carter rallies the Tharks to ride for Zodanga to prevent them from destroying Helium.